CVE-2026-76505

CVE Enrichment

CVSS: 7.5 HIGH
CISA KEV: Not listed

Description

A vulnerability in the IPv4 packet processing functionality of Cisco IOS XR Software that affects Cisco ASR 9000 and 9900 Series Aggregation Services Routers as well as Cisco ASR 9902 and 9903 Compact High-Performance Routers could allow an unauthenticated, remote attacker to cause network processor (NP) errors, resulting in a line card reset or shutdown and a denial of service (DoS) condition.  This vulnerability is due to the incorrect handling of crafted IPv4 packets that are received on an affected line card interface and processed as for-us traffic. The issue can result in an NP reset, causing traffic loss on the affected line card while it recovers. Under repeated reset conditions, the network processor may enter a persistent shutdown state, in which case an explicit line card reload may be required to restore traffic. The vulnerability is within the IPv4 packet-processing path. Transit IPv4 traffic does not trigger this issue and IPv6 traffic cannot trigger it.

Technical Details

CVSS Version: 3.1
CNA / NVD Source: [email protected]
Published: 22-Oct-2026 00:19
Last Modified: 22-Oct-2026 21:17
CWE: CWE-20

CVSS Vector


            CVSS:3.1                            AV:N /
                            AC:L /
                            PR:N /
                            UI:N /
                            S:U /
                            C:N /
                            I:N /
                            A:H

References

[email protected]

Last enrichment sync: 22-Oct-2026 21:31
Sources: NVD · FIRST EPSS · CISA KEV
Latest successful provider update; providers refresh independently.

Reported Context (1)

Cisco patched a high-severity denial-of-service (DoS) vulnerability in IOS XR, tracked as CVE-2026-76505, and a high-severity privilege escalation bug in Secure Client’s Secure Firewall Posture module Cisco Patches 34 Vulnerabilities Across Multiple Products

CVE (7)

Vendors (1)

Products (18)

Note: Related entities, including threat actors, malware, CVEs, MITRE ATT&CK techniques, vendors, products, tools, countries, and industries, are shown when they appear in the same reporting. Their presence does not necessarily mean they were targeted, compromised, vulnerable, responsible for the activity, or directly involved in the incident.